Switching a Face-to-Face Survey to Self-Completion in Germany: Considering the Impact of Survey Mode Design on Response Rate, Sample Composition, and Response Patterns in the European Social Survey

Abstract

The European Social Survey (ESS) is a repeated cross-national survey program adhering to rigorous methodological standards, especially regarding comparability. The COVID-19 pandemic challenged some of these standards by preventing the implementation of the face-to-face mode of data collection in some of the participating countries. Germany and other countries switched to web- and paper-based self-completion modes, marking a stark deviation from previous ESS rounds. In this paper, we examine the impact of the mode switch on response rates, bias in the sample composition (e.g., age, education, migration background), and response behavior (e.g., item nonresponse, response patterns) by comparing the German self-completion ESS (Round 10) with the preceding and the succeeding face-to-face rounds. We found a much higher and more regionally balanced response rate in the self-completion ESS and small differences in bias in sample composition and response behavior between rounds. Within Round 10, respondents choosing the web mode differed in sociodemographic characteristics from those who completed the paper-based questionnaire.